4. arthur plants 4 basil plants in a square frame like
the one shown. the soil in this frame will be
2x in, deep.

part a
write a polynomial function v in standard
form to represent the volume of soil in the
xin.
frame in terms of x. explain your reasoning,
and identify the polynomial identities and
other properties you used, no need to put in expanded form!
txin.

The first thing to remember is that when you have a zero of 3i, you will also have a zero of -3i. This is because of the way imaginary solutions are created (taking the square root of a negative number). When you take the sqrt you get TWO answers.
The factors for these zeros are (x - 3i)(x+3i)(x+2)(x-1)
When you multiply the factors, the polynomial will be:
x^4 + x^3 + 7x^2 + 9x - 18